1. Field of the Invention
The present invention relates to a musical content data processing apparatus which loads encrypted musical content material data sets contained in musical contents into an electronic musical apparatus so that the electronic musical apparatus can use the loaded musical content material data for processing such as generation of musical tone signals.
2. Description of the Related Art
In some cases, conventionally, an electronic musical apparatus such as an electronic musical instrument downloads an encrypted musical content file from a musical content distribution server and uses the downloaded file. For example, an electronic musical apparatus disclosed in Japanese Unexamined Patent Publication No. 2005-195673 takes a desired musical content material data set out of combined musical content data having encrypted musical content material data sets, decrypts the desired musical content material data set, and uses the decrypted musical content material data set.
According to this conventional art, in order to allow decryption only of musical content material data of such kinds as are available on the electronic musical apparatus, kind information of respective musical content material data sets is described in a security information chunk in order to identify musical content material data of available kinds on the basis of the kind information. By such a manner, the conventional art enables the use of the desired musical content material data set without the need for decrypting all the encrypted musical content material data sets. In a case where there are a multiplicity of musical content material data sets of the same kind, however, the conventional art requires decryption of all the musical content material data sets of this kind.